Refrigeration cycle apparatus

ABSTRACT

A refrigeration cycle apparatus includes a compressor, a first heat exchanger, a decompressing device, a second heat exchanger, a first switching valve, a second switching valve, and a controller. The first switching valve is switched to one of a first state and a second state. The second switching valve is switched to one of a third state, a fourth state, and a fifth state. When switching to a second cooling operation to bring the first and second switching valves into the second and fourth states respectively, is requested during a first cooling operation to bring the first and second switching valves into the first and third states, respectively, the controller performs a first switching operation to bring the first switching valve into the second state and bring the second switching valve into the fifth state, and thereafter switches the first switching operation to the second cooling operation.

TECHNICAL FIELD

The present disclosure relates to a refrigeration cycle apparatus.

BACKGROUND ART

Japanese Patent Laying-Open No. 2005-134099 (PTL 1) discloses arefrigeration cycle apparatus including a refrigerant circuit thatincludes a compressor, a first heat exchanger, a decompressing device, asecond heat exchanger, and a flow path switching valve. In thisrefrigeration cycle apparatus, the state of the flow path switchingvalve is switched to thereby allow switching between the first operationand the second operation. In the first operation, refrigerant circulatesthrough the compressor, the first heat exchanger, the decompressingdevice, and the second heat exchanger sequentially in this order. In thesecond operation, refrigerant circulates through the compressor, thesecond heat exchanger, the decompressing device, and the first heatexchanger sequentially in this order.

CITATION LIST Patent Literature

PTL 1: Japanese Patent Laying-Open No. 2005-134099

SUMMARY OF INVENTION Technical Problem

The pressure distribution of the refrigerant is different between thefirst operation and the second operation. Specifically, in the firstoperation, high-pressure refrigerant is distributed in the first heatexchanger and low-pressure refrigerant is distributed in the second heatexchanger. In contrast, in the second operation, high-pressurerefrigerant is distributed in the second heat exchanger and low-pressurerefrigerant is distributed in the first heat exchanger. Thus, when theoperation is switched from one to the other between the first operationand the second operation, the pressure distribution of the refrigerantcollapses. This leads to a concern that such a distribution collapse mayincrease the time required for the refrigeration cycle to stabilizeafter the operation is switched.

The present disclosure has been made in order to solve theabove-described problems. An object of the present disclosure is toreduce the time required for a refrigeration cycle to stabilize after anoperation is switched in a refrigeration cycle apparatus switchablebetween a first operation and a second operation. In the firstoperation, refrigerant circulates in order of a compressor, a first heatexchanger, a decompressing device, and a second heat exchanger. In thesecond operation, refrigerant circulates in order of the compressor, thesecond heat exchanger, the decompressing device, and the first heatexchanger.

Solution to Problem

A refrigeration cycle apparatus according to the present disclosure is arefrigeration cycle apparatus switchable between a first operation and asecond operation. In the first operation, refrigerant circulates inorder of a compressor, a first heat exchanger, a decompressing device,and a second heat exchanger. In the second operation, the refrigerantcirculates in order of the compressor, the second heat exchanger, thedecompressing device, and the first heat exchanger. The refrigerationcycle apparatus includes: a first switching valve connected to adischarge port of the compressor, one port of the first heat exchanger,one port of the second heat exchanger, and one port of the decompressingdevice; a second switching valve connected to a suction port of thecompressor, the other port of the first heat exchanger, the other portof the second heat exchanger, and the other port of the decompressingdevice; and a controller configured to control the first switching valveand the second switching valve.

The first switching valve is configured to be switchable to one of afirst state and a second state. In the first state, the discharge portof the compressor is connected to the one port of the first heatexchanger, and the one port of the second heat exchanger is connected tothe one port of the decompressing device. In the second state, thedischarge port of the compressor is connected to the one port of thesecond heat exchanger, and the one port of the first heat exchanger isconnected to the one port of the decompressing device.

The second switching valve is configured to be switchable to one of athird state, a fourth state, and a fifth state. In the third state, theother port of the first heat exchanger is connected to the other port ofthe decompressing device, and the other port of the second heatexchanger is connected to the suction port of the compressor. In thefourth state, the other port of the second heat exchanger is connectedto the other port of the decompressing device, and the other port of thefirst heat exchanger is connected to the suction port of the compressor.In the fifth state, the other port of the decompressing device isconnected to the suction port of the compressor, and the other port ofthe first heat exchanger is disconnected from the other port of thesecond heat exchanger.

The controller is configured to set the first switching valve to thefirst state and set the second switching valve to the third state duringthe first operation, and set the first switching valve to the secondstate and set the second switching valve to the fourth state during thesecond operation.

When switching to the second operation is requested during the firstoperation, the controller is configured to perform a first switchingoperation to bring the first switching valve into the second state andbring the second switching valve into the fifth state, and switch anoperation of the refrigeration cycle apparatus to the second operationafter performing the first switching operation.

Advantageous Effects of Invention

According to the present disclosure, the time required for therefrigeration cycle to stabilize after switching of the operation can bereduced in the refrigeration cycle apparatus switchable between thefirst operation and the second operation. In the first operation,refrigerant circulates in order of the compressor, the first heatexchanger, the decompressing device, and the second heat exchanger. Inthe second operation, refrigerant circulates in order of the compressor,the second heat exchanger, the decompressing device, and the first heatexchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram schematically showing an example of an overallconfiguration of a refrigeration cycle apparatus according to a presentfirst embodiment.

FIG. 2 is a perspective view showing an example of an internal structureof a second switching valve.

FIG. 3 is a diagram showing a rotational position of a valve body whenthe second switching valve is in a third state.

FIG. 4 is a diagram showing the rotational position of the valve bodywhen the second switching valve is in a fourth state.

FIG. 5 is a diagram showing a rotational position of the valve body whenthe second switching valve is in a fifth state.

FIG. 6 is a diagram (first diagram) showing a state during a firstcooling operation of a refrigerant circuit.

FIG. 7 is a diagram (first diagram) showing a state during a secondcooling operation of the refrigerant circuit.

FIG. 8 is a diagram (first diagram) showing a state during a firstswitching operation of the refrigerant circuit.

FIG. 9 is a diagram (first diagram) showing a state during a secondswitching operation of the refrigerant circuit.

FIG. 10 is a diagram showing an example of transition of an operationstate of the refrigeration cycle apparatus.

FIG. 11 is a diagram (second diagram) showing a state during the firstcooling operation of the refrigerant circuit.

FIG. 12 is a diagram (second diagram) showing a state during the firstswitching operation of the refrigerant circuit.

FIG. 13 is a diagram (second diagram) showing a state during the secondcooling operation of the refrigerant circuit.

FIG. 14 is a diagram (second diagram) showing a state during the secondswitching operation of the refrigerant circuit.

FIG. 15 is a diagram (third diagram) showing a state during the firstcooling operation of the refrigerant circuit.

FIG. 16 is a diagram (third diagram) showing a state during the firstswitching operation of the refrigerant circuit.

FIG. 17 is a diagram (third diagram) showing a state during the secondcooling operation of the refrigerant circuit.

FIG. 18 is a diagram (third diagram) showing a state during the secondswitching operation of the refrigerant circuit.

FIG. 19 is a diagram (first diagram) showing a configuration example ofa first air blower and a second air blower.

FIG. 20 is a diagram (second diagram) showing a configuration example ofthe first air blower and the second air blower.

FIG. 21 is a diagram (third diagram) showing a configuration example ofthe first air blower and the second air blower.

FIG. 22 is a diagram (fourth diagram) showing a configuration example ofthe first air blower and the second air blower.

FIG. 23 is a diagram (fifth diagram) showing a configuration example ofthe first air blower and the second air blower.

FIG. 24 is a diagram (sixth diagram) showing a configuration example ofthe first air blower and the second air blower.

DESCRIPTION OF EMBODIMENTS

The following describes embodiments of the present disclosure in detailwith reference to the accompanying drawings. While a plurality ofembodiments will be described below, it has been originally intended atthe time of filing of the present application to appropriately combinethe configurations described in the embodiments. In the accompanyingdrawings, the same or corresponding components are denoted by the samereference characters, and description thereof will not be repeated.

First Embodiment

[Description of Configuration]

FIG. 1 is a diagram schematically showing an example of an overallconfiguration of a refrigeration cycle apparatus 1 according to thepresent first embodiment. Refrigeration cycle apparatus 1 includes arefrigerant circuit RC, a first air blower 80, a second air blower 90,and a controller 100. Refrigerant circuit RC includes a compressor 10, afirst heat exchanger 20, a decompressing device 30, a second heatexchanger 40, pipes 51 to 58, a first switching valve 60, and a secondswitching valve 70.

In refrigerant circuit RC, compressor 10, first heat exchanger 20,decompressing device 30, and second heat exchanger 40 are connected bypipes 51 to 58, first switching valve 60, and second switching valve 70to thereby form a circulation flow path through which refrigerantcirculates. Inside refrigerant circuit RC, refrigerant involving a phasechange, such as carbon dioxide or R410A, circulates.

Compressor 10 has a suction port connected to pipe 58, and a dischargeport connected to pipe 51. Compressor 10 suctions low-pressurerefrigerant from pipe 58, compresses the suctioned refrigerant, and thendischarges the compressed refrigerant as high-pressure refrigerant topipe 51. The rotation speed of compressor 10 is adjusted in response toa command from controller 100. Compressor 10 discharges refrigerant at aflow rate corresponding to the rotation speed. The flow rate of therefrigerant circulating through refrigeration cycle apparatus 1 iscontrolled by adjusting the rotation speed (the discharge flow rate) ofcompressor 10.

First heat exchanger 20 and second heat exchanger 40 each are a heatexchanger having a flow path through which refrigerant flows. In each offirst heat exchanger 20 and second heat exchanger 40, heat is exchangedbetween the refrigerant flowing through the flow path and the airoutside the flow path.

Decompressing device 30 decompresses high-pressure refrigerant. Examplesof decompressing device 30 usable herein include a device having a valvebody capable of adjusting a degree of opening in response to a commandfrom controller 100, such as an electronic control type expansion valve.

First switching valve 60 is a four-way valve having: a port connected tothe discharge port of compressor 10 via pipe 51; a port connected to oneport of first heat exchanger 20 via pipe 52; a port connected to oneport of second heat exchanger 40 via pipe 56; and a port connected toone port of decompressing device 30 via pipe 55.

First switching valve 60 is switched to one of the first state and thesecond state in response to a command from controller 100.

When first switching valve 60 is in the first state, pipe 51 isconnected to pipe 52, and pipe 56 is connected to pipe 55. Thereby, thedischarge port of compressor 10 is connected to one port of first heatexchanger 20, and one port of second heat exchanger 40 is connected toone port of decompressing device 30. Note that FIG. 1 illustrates thecase where first switching valve 60 is set in the first state.

When first switching valve 60 is in the second state, pipe 51 isconnected to pipe 56, and pipe 52 is connected to pipe 55. Thereby, thedischarge port of compressor 10 is connected to one port of second heatexchanger 40, and one port of first heat exchanger 20 is connected toone port of decompressing device 30.

Second switching valve 70 is a four-way valve having: a port connectedto the suction port of compressor 10 via pipe 58; a port connected tothe other port of first heat exchanger 20 via pipe 53; a port connectedto the other port of second heat exchanger 40 via pipe 57; and a portconnected to the other port of decompressing device 30 via pipe 54.

Second switching valve 70 is switched to one of the third state, thefourth state, and the fifth state in response to a command fromcontroller 100.

When second switching valve 70 is in the third state, pipe 53 isconnected to pipe 54 and pipe 57 is connected to pipe 58. Thereby, theother port of first heat exchanger 20 is connected to the other port ofdecompressing device 30, and the other port of second heat exchanger 40is connected to the suction port of compressor 10. Note that FIG. 1illustrates the case where second switching valve 70 is set in the thirdstate.

When second switching valve 70 is in the fourth state, pipe 57 isconnected to pipe 54, and pipe 53 is connected to pipe 58. Thereby, theother port of second heat exchanger 40 is connected to the other port ofdecompressing device 30, and the other port of first heat exchanger 20is connected to the suction port of compressor 10.

When second switching valve 70 is in the fifth state, pipe 54 isconnected to pipe 58, and pipe 53 and pipe 57 are disconnected from eachother. Thereby, the suction port of compressor 10 is connected to theother port of decompressing device 30, and the other port of first heatexchanger 20 and the other port of second heat exchanger 40 aredisconnected from each other.

FIG. 2 is a perspective view showing an example of the internalstructure of second switching valve 70. Second switching valve 70includes: a container 71 having a hollow cylindrical shape and providedwith four ports connected to respective pipes 53, 54, 57, and 58; and avalve body 72 having a cylindrical shape and accommodated in container71. Valve body 72 is configured to be rotatable about a rotation axis 76in response to a command from controller 100.

FIG. 3 is a diagram showing the rotational position of valve body 72when second switching valve 70 is in the third state. FIG. 4 is adiagram showing the rotational position of valve body 72 when secondswitching valve 70 is in the fourth state. FIG. 5 is a diagram showingthe rotational position of valve body 72 when second switching valve 70is in the fifth state.

As shown in FIGS. 3 to 5 , three flow paths 73, 74 and 75 independent ofeach other are provided inside valve body 72. When second switchingvalve 70 is in the third state, as shown in FIG. 3 , pipes 54 and 53 areconnected to each other through flow path 73 of valve body 72, and pipes57 and 58 are connected to each other through flow path 74 of valve body72. Thereby, the other port of first heat exchanger 20 is connected tothe other port of decompressing device 30, and the other port of secondheat exchanger 40 is connected to the suction port of compressor 10.

When second switching valve 70 is in the fourth state, as shown in FIG.4 , pipes 54 and 57 are connected to each other through flow path 74 ofvalve body 72, and pipes 53 and 58 are connected to each other throughflow path 73 of valve body 72. Thereby, the other port of second heatexchanger 40 is connected to the other port of decompressing device 30,and the other port of first heat exchanger 20 is connected to thesuction port of compressor 10.

When second switching valve 70 is in the fifth state, as shown in FIG. 5, pipes 54 and 58 are connected to each other through flow path 75 ofvalve body 72, whereas pipes 53 and 57 are disconnected from each otherby valve body 72. Thereby, the suction port of compressor 10 isconnected to the other port of decompressing device 30, and the otherport of first heat exchanger 20 and the other port of second heatexchanger 40 are disconnected from each other.

Referring back to FIG. 1 , first air blower 80 is configured to becapable of blowing air on the indoor side as a target to be cooled (theair will be hereinafter simply referred to as “indoor air”), in responseto a command from controller 100. Further, first air blower 80 isconfigured to be capable of switching the supply destination of theindoor air between first heat exchanger 20 and second heat exchanger 40.

Second air blower 90 is configured to be capable of blowing air on theoutdoor side as a target not to be cooled (the air will be hereinaftersimply referred to as “outdoor air”), in response to a command fromcontroller 100. Further, second air blower 90 is configured to becapable of switching the supply destination of the outdoor air betweenfirst heat exchanger 20 and second heat exchanger 40.

Controller 100 is configured to include a central processing unit (CPU),a memory, and an input/output port through which various signals areinput and output. Based on signals from each sensor and device, aprogram stored in the memory, and the like, controller 100 controls eachdevice (compressor 10, decompressing device 30, first switching valve60, second switching valve 70, first air blower 80, second air blower90, and the like) of refrigeration cycle apparatus 1. Note that thecontrol performed by controller 100 is not limited to processing bysoftware and may be performed by dedicated hardware (an electroniccircuit).

[First and Second Cooling Operations]

In refrigeration cycle apparatus 1, the states of first switching valve60 and second switching valve 70 are switched to thereby allow switchingbetween the first cooling operation and the second cooling operation.

FIG. 6 is a diagram showing the state during the first cooling operationof refrigerant circuit RC. During the first cooling operation,controller 100 operates compressor 10, and also, brings first switchingvalve 60 into the first state and brings second switching valve 70 intothe third state.

During the first cooling operation, the refrigerant circulates throughcompressor 10, first heat exchanger 20, decompressing device 30, andsecond heat exchanger 40 sequentially in this order, so that first heatexchanger 20 functions as a condenser and second heat exchanger 40functions as an evaporator. More specifically, the high-temperature andhigh-pressure refrigerant discharged from compressor 10 flows into firstheat exchanger 20 through first switching valve 60. The high-temperatureand high-pressure refrigerant exchanges heat with the outside air infirst heat exchanger 20, and thus, decreases in temperature and flowsout of first heat exchanger 20. The refrigerant flowing out of firstheat exchanger 20 is decompressed by decompressing device 30, turns intolow-temperature and low-pressure refrigerant, and then, flows intosecond heat exchanger 40. The low-temperature and low-pressurerefrigerant exchanges heat with the outside air in second heat exchanger40, and thus, rises in temperature and flows out of second heatexchanger 40. The refrigerant flowing out of second heat exchanger 40 issuctioned into compressor 10 through second switching valve 70.

Thus, during the first cooling operation, the high-pressure refrigerantis distributed through pipes 51 and 52, first heat exchanger 20, andpipes 53 and 54, and the low-pressure refrigerant is distributed throughpipes 55 and 56, second heat exchanger 40, and pipes 57 and 58.

During the first cooling operation, controller 100 controls first airblower 80 and second air blower 90 such that the supply destination ofthe indoor air is set to second heat exchanger 40 and the supplydestination of the outdoor air is set to first heat exchanger 20. Thisfacilitates exchange of heat between first heat exchanger 20 functioningas a condenser and the outdoor air not to be cooled, and alsofacilitates exchange of heat between second heat exchanger 40functioning as an evaporator and the indoor air to be cooled. Thereby,the indoor air to be cooled can be efficiently cooled. Note that FIG. 1illustrates the state during the first cooling operation.

FIG. 7 is a diagram showing the state during the second coolingoperation of refrigerant circuit RC. During the second coolingoperation, controller 100 operates compressor 10, and also, brings firstswitching valve 60 into the second state and brings second switchingvalve 70 into the fourth state.

During the second cooling operation, the refrigerant circulates throughcompressor 10, second heat exchanger 40, decompressing device 30, andfirst heat exchanger 20 sequentially in this order, and thus, secondheat exchanger 40 functions as a condenser and first heat exchanger 20functions as an evaporator. More specifically, the high-temperature andhigh-pressure refrigerant discharged from compressor 10 flows intosecond heat exchanger 40 through first switching valve 60. Thehigh-temperature and high-pressure refrigerant exchanges heat with theoutside air in second heat exchanger 40, and thus, decreases intemperature and flows out of second heat exchanger 40. The refrigerantflowing out of second heat exchanger 40 is decompressed by decompressingdevice 30, turns into low-temperature and low-pressure refrigerant, andthen, flows into first heat exchanger 20. The low-temperature andlow-pressure refrigerant exchanges heat with the outside air in firstheat exchanger 20, and thus, rises in temperature and flows out of firstheat exchanger 20. The refrigerant flowing out of first heat exchanger20 is suctioned into compressor 10 through second switching valve 70.

Thus, during the second cooling operation, the high-pressure refrigerantis distributed through pipes 51 and 56, second heat exchanger 40, andpipes 57 and 54, and the low-pressure refrigerant is distributed throughpipes 55 and 52, first heat exchanger 20, and pipes 53 and 58.

Further, during the second cooling operation, controller 100 controlsfirst air blower 80 and second air blower 90 such that the supplydestination of the indoor air is set to first heat exchanger 20 and thesupply destination of the outdoor air is set to second heat exchanger40. This facilitates exchange of heat between second heat exchanger 40functioning as a condenser and the outdoor air not to be cooled, andalso facilitates exchange of heat between first heat exchanger 20functioning as an evaporator and the indoor air to be cooled. Thereby,also during the second cooling operation, the indoor air to be cooledcan be efficiently cooled.

During the first cooling operation, for example, when the temperature ofthe refrigerant inside second heat exchanger 40 functioning as anevaporator becomes equal to or lower than 0° C., frost forms on secondheat exchanger 40, which makes it difficult for air to flowtherethrough, with the result that the heat exchange efficiency insecond heat exchanger 40 may deteriorate. Thus, when frost forms onsecond heat exchanger 40 during the first cooling operation (forexample, when the temperature of the refrigerant in second heatexchanger 40 detected by a sensor (not shown) falls below a referencevalue close to 0° C.), controller 100 determines that switching to thesecond cooling operation is requested, and then, switches the operationto the second cooling operation. Thereby, second heat exchanger 40functioning as an evaporator comes to function as a condenser, andthereby, frost forming on second heat exchanger 40 can be removed.

Further, in the present embodiment, the supply destination of the indoorair is set to first heat exchanger 20 functioning as an evaporatorduring the second cooling operation, and therefore, cold air can bedelivered to the indoor side also during the second cooling operation.

During the second cooling operation, when frost forms on first heatexchanger 20 functioning as a condenser (for example, when thetemperature of the refrigerant in first heat exchanger 20 detected by asensor (not shown) falls below a reference value close to 0° C.),controller 100 determines that switching to the first cooling operationis requested, and then, switches the operation to the first coolingoperation. Thereby, first heat exchanger 20 functioning as an evaporatorcomes to function as a condenser, and thereby, frost forming on firstheat exchanger 20 can be removed.

[First and Second Switching Operations]

As described above, during the first cooling operation, thehigh-pressure refrigerant is distributed in first heat exchanger 20, andthe low-pressure refrigerant is distributed in second heat exchanger 40.In contrast, during the second cooling operation, the high-pressurerefrigerant is distributed in second heat exchanger 40, and thelow-pressure refrigerant is distributed in first heat exchanger 20.Thus, when the operation is switched from one to the other between thefirst cooling operation and the second cooling operation, the pressuredistribution of the refrigerant collapses. This leads to a concern thatsuch a distribution collapse may increase the time required for therefrigeration cycle to stabilize after the operation is switched.

In view of such a problem, when switching to the second coolingoperation is requested during the first cooling operation, controller100 according to the present embodiment performs the “first switchingoperation” to bring first switching valve 60 into the second state andbring second switching valve 70 into the fifth state. Then, after thefirst switching operation is performed for a certain time period,controller 100 switches the operation of refrigeration cycle apparatus 1to the second cooling operation.

FIG. 8 is a diagram showing the state during the first switchingoperation of refrigerant circuit RC. As shown in FIG. 8 , during thefirst switching operation, controller 100 operates compressor 10, andalso, brings first switching valve 60 into the second state and bringssecond switching valve 70 into the fifth state.

The first switching operation is performed before the first coolingoperation is switched to the second cooling operation. Thereby, therefrigerant inside first heat exchanger 20 in which the pressure israised high during the first cooling operation is recovered intocompressor 10, so that the inside of first heat exchanger 20 can be setin the low pressure state. Also, the high-pressure refrigerant fromcompressor 10 is supplied into second heat exchanger 40 in which thepressure is reduced low during the first cooling operation, so that theinside of second heat exchanger 40 can be set in the high pressurestate. In other words, before switching to the second cooling operation,the inside of first heat exchanger 20 can be set in the low pressurestate in advance and the inside of second heat exchanger 40 can be setin the high pressure state in advance.

In particular, during the first switching operation, second switchingvalve 70 is brought into the fifth state, and thereby, the other port offirst heat exchanger 20 and the other port of second heat exchanger 40are disconnected from each other by second switching valve 70. This canprevent the high-pressure refrigerant and the low-pressure refrigerantfrom being mixed and equalized in pressure. Thus, as compared with thecase where the first cooling operation is simply switched to the secondcooling operation, the inside of first heat exchanger 20 can be set inthe low pressure state in the early stage, and the inside of second heatexchanger 40 can be set in the high pressure state in the early stage.

Further, during the first switching operation, controller 100 stopsblowing of air by first air blower 80 and second air blower 90. Thus,during the first switching operation, blowing of air into first heatexchanger 20 and second heat exchanger 40 is stopped. Accordingly, theinside of first heat exchanger 20 can be set in the low pressure statein the earlier stage, and the inside of second heat exchanger 40 can beset in the high pressure state in the earlier stage.

After performing the first switching operation for a certain timeperiod, controller 100 switches the operation of refrigeration cycleapparatus 1 to the second cooling operation. This can reduce the timerequired for the refrigeration cycle to stabilize after switching to thesecond cooling operation.

Further, when switching to the first cooling operation is requestedduring the second cooling operation, controller 100 according to thepresent embodiment performs the “second switching operation” to bringfirst switching valve 60 into the first state and bring second switchingvalve 70 into the fifth state. Then, after performing the secondswitching operation for a certain time period, controller 100 switchesthe operation to the first cooling operation.

FIG. 9 is a diagram showing the state during the second switchingoperation of refrigerant circuit RC. As shown in FIG. 9 , during thesecond switching operation, controller 100 operates compressor 10, andalso, brings first switching valve 60 into the first state and bringssecond switching valve 70 into the fifth state.

The second switching operation is performed before the second coolingoperation is switched to the first cooling operation. Thereby, therefrigerant inside second heat exchanger 40 in which the pressure israised high during the second cooling operation is recovered intocompressor 10, so that the inside of second heat exchanger 40 can be setin the low pressure state. Also, the high-pressure refrigerant fromcompressor 10 is supplied into first heat exchanger 20 in which thepressure is reduced low during the second cooling operation, so that theinside of first heat exchanger 20 can be set in the high pressure state.In other words, before switching to the first cooling operation, theinside of second heat exchanger 40 can be set in the low pressure statein advance and the inside of first heat exchanger 20 can be set in thehigh pressure state in advance.

In particular, during the second switching operation, second switchingvalve 70 is brought into the fifth state, and thereby, the other port offirst heat exchanger 20 and the other port of second heat exchanger 40are disconnected from each other by second switching valve 70. This canprevent the high-pressure refrigerant and the low-pressure refrigerantfrom being mixed and equalized in pressure. Therefore, the inside ofsecond heat exchanger 40 can be set in the low pressure state in theearly stage, and the inside of first heat exchanger 20 can be set in thehigh pressure state in the early stage.

Further, during the second switching operation, controller 100 stopsblowing of air by first air blower 80 and second air blower 90. Thereby,during the second switching operation, blowing of air into first heatexchanger 20 and second heat exchanger 40 is stopped. Accordingly, theinside of second heat exchanger 40 can be set in the low pressure statein the earlier stage, and the inside of first heat exchanger 20 can beset in the high pressure state in the earlier stage.

After performing the second switching operation for a certain timeperiod, controller 100 switches the operation of refrigeration cycleapparatus 1 to the first cooling operation. This can reduce the timerequired for the refrigeration cycle to stabilize after switching to thefirst cooling operation.

FIG. 10 is a diagram showing an example of transition of the operationstate of refrigeration cycle apparatus 1 controlled by controller 100.In FIG. 10 , the horizontal axis represents time while the vertical axisrepresents, sequentially from the top, the state of compressor 10, thestate of first switching valve 60, the state of second switching valve70, the supply destination of indoor air, and the supply destination ofoutdoor air.

Before time t1, the first cooling operation is performed. During thefirst cooling operation, controller 100 brings first switching valve 60into the first state and brings second switching valve 70 into the thirdstate. Further, controller 100 controls first air blower 80 such thatthe supply destination of the indoor air is set to second heat exchanger40, and controls second air blower 90 such that the supply destinationof the outdoor air is set to first heat exchanger 20.

When switching to the second cooling operation is requested at time t1during the first cooling operation, controller 100 switches theoperation of refrigeration cycle apparatus 1 from the first coolingoperation to the first switching operation. Specifically, controller 100switches first switching valve 60 from the first state to the secondstate, and switches second switching valve 70 from the third state tothe fifth state. Further, controller 100 stops blowing of the indoor airby first air blower 80 and stops blowing of the outdoor air by secondair blower 90.

At time t2 at which a certain time period has elapsed since the start ofthe first switching operation, controller 100 switches the operation ofrefrigeration cycle apparatus 1 from the first switching operation tothe second cooling operation.

Specifically, controller 100 switches second switching valve 70 from thefifth state to the fourth state while maintaining first switching valve60 in the second state. Further, controller 100 controls first airblower 80 to switch the supply destination of the indoor air from secondheat exchanger 40 to first heat exchanger 20, and also controls secondair blower 90 to switch the supply destination of the outdoor air fromfirst heat exchanger 20 to second heat exchanger 40.

When switching to the first cooling operation is requested at time t3during the second cooling operation, controller 100 switches theoperation of refrigeration cycle apparatus 1 from the second coolingoperation to the second switching operation. Specifically, controller100 switches first switching valve 60 from the second state to the firststate, and switches second switching valve 70 from the fourth state tothe fifth state. Further, controller 100 stops blowing of the indoor airby first air blower 80 and also stops blowing of the outdoor air bysecond air blower 90.

At time t4 at which a certain time period has elapsed since the start ofthe second switching operation, controller 100 switches the operation ofrefrigeration cycle apparatus 1 from the second switching operation tothe first cooling operation. Specifically, controller 100 switchessecond switching valve 70 from the fifth state to the third state whilemaintaining first switching valve 60 in the first state. Further,controller 100 controls first air blower 80 to switch the supplydestination of the indoor air from first heat exchanger 20 to secondheat exchanger 40, and also controls second air blower 90 to switch thesupply destination of the outdoor air from second heat exchanger 40 tofirst heat exchanger 20.

Also at and after time t5, switching similar to that performed untiltime t5 is performed.

As described above, when switching to the second cooling operation isrequested during the first cooling operation, controller 100 accordingto the present embodiment performs the “first switching operation” tobring first switching valve 60 into the second state and bring secondswitching valve 70 into the fifth state, for a certain time periodbefore switching to the second cooling operation. Thus, as compared withthe case where the first cooling operation is simply switched to thesecond cooling operation, the high-pressure refrigerant and thelow-pressure refrigerant can be prevented from being mixed and equalizedin pressure during switching of the operation, and also, the operationcan be switched to the second cooling operation after the distributionstate close to the pressure distribution in the second cooling operationis achieved in advance in the early stage. This can reduce the timerequired for the refrigeration cycle to stabilize after switching to thesecond cooling operation. As a result, wasteful energy consumed tostabilize the refrigeration cycle after switching to the second coolingoperation can be reduced, to thereby allow energy saving forrefrigeration cycle apparatus 1.

Further, when switching to the first cooling operation is requestedduring the second cooling operation, controller 100 according to thepresent embodiment performs the “second switching operation” to bringfirst switching valve 60 into the first state and bring second switchingvalve 70 into the fifth state, for a certain time period beforeswitching to the first cooling operation. Thereby, as compared with thecase where the second cooling operation is simply switched to the firstcooling operation, the high-pressure refrigerant and the low-pressurerefrigerant can be prevented from being mixed and equalized in pressureduring switching of the operation, and also, the operation can beswitched to the first cooling operation after the distribution stateclose to the pressure distribution in the first cooling operation isachieved in advance in the early stage. This can reduce the timerequired for the refrigeration cycle to stabilize after switching to thefirst cooling operation. As a result, wasteful energy consumed tostabilize the refrigeration cycle after switching to the first coolingoperation can be reduced, to thereby allow energy saving forrefrigeration cycle apparatus 1.

Second Embodiment

FIGS. 11 to 14 each schematically show an example of the configurationof a refrigerant circuit RCa of a refrigeration cycle apparatusaccording to the present second embodiment. Refrigerant circuit RCaaccording to the present second embodiment is obtained by adding adecompressing device 32 and a third heat exchanger 42 to refrigerantcircuit RC according to the first embodiment. Other configurations ofrefrigerant circuit RCa are the same as those of refrigerant circuit RC.Further, other configurations and operations of the refrigeration cycleapparatus according to the present second embodiment are the same asthose of refrigeration cycle apparatus 1 shown in FIG. 1 describedabove.

Decompressing device 32 and third heat exchanger 42 are disposed betweensecond switching valve 70 and the suction port of compressor 10.

Decompressing device 32 decompresses the refrigerant from secondswitching valve 70 and outputs the decompressed refrigerant to thirdheat exchanger 42. Examples of decompressing device 32 usable hereininclude a device having a valve body capable of adjusting the degree ofopening in response to a command from controller 100, such as anelectronic control type expansion valve.

Third heat exchanger 42 exchanges heat between the refrigerantdecompressed by decompressing device 32 and the outside air.

FIG. 11 is a diagram showing the state during the first coolingoperation of refrigerant circuit RCa. FIG. 12 is a diagram showing thestate during the first switching operation of refrigerant circuit RCa.FIG. 13 is a diagram showing the state during the second coolingoperation of refrigerant circuit RCa. FIG. 14 is a diagram showing thestate during the second switching operation of refrigerant circuit RCa.

The states of compressor 10, first switching valve 60, second switchingvalve 70, first air blower 80, and second air blower 90 during eachoperation are controlled basically in the same manner as that in theabove-described first embodiment.

In refrigerant circuit RCa according to the present second embodiment,however, due to addition of decompressing device 32, during eachoperation, high-pressure refrigerant is distributed in the circuitextending from the discharge port of compressor 10 to decompressingdevice 30, medium-pressure refrigerant is distributed in the circuitextending from decompressing device 30 to decompressing device 32, andlow-pressure refrigerant is distributed in the circuit extending fromdecompressing device 32 to the suction port of compressor 10.

Further, as shown in FIG. 11 , refrigerant circuit RCa according to thepresent second embodiment is configured such that indoor air is blownthrough second heat exchanger 40 and third heat exchanger 42sequentially in this order during the first cooling operation. In otherwords, during the first cooling operation, second heat exchanger 40 andthird heat exchanger 42 function as evaporators, and the indoor airflows through second heat exchanger 40 and thereafter is blown to thirdheat exchanger 42.

In this way, in the present second embodiment, the indoor air is blownthrough second heat exchanger 40 and third heat exchanger 42sequentially in this order during the first cooling operation. Thus,among second heat exchanger 40 and third heat exchanger 42 eachfunctioning as an evaporator during the first cooling operation (i.e., aheat exchanger on which frost may form), second heat exchanger 40functioning as a condenser after switching to the second coolingoperation can be positively covered with frost, and third heat exchanger42 functioning as an evaporator also after switching to the secondcooling operation can be less likely to be covered with frost. As aresult, when the operation is thereafter switched to the second coolingoperation for defrosting, only second heat exchanger 40 significantlycovered with frost can be defrosted, so that an efficient defrostingoperation can be performed.

Further, in refrigerant circuit RCa according to the present secondembodiment, the indoor air is blown through first heat exchanger 20 andthird heat exchanger 42 sequentially in this order during the secondcooling operation, as shown in FIG. 13 . In other words, during thesecond cooling operation, first heat exchanger 20 and third heatexchanger 42 function as evaporators, and the indoor air flows throughfirst heat exchanger 20 and thereafter is blown to third heat exchanger42.

In this way, in the present second embodiment, the indoor air is blownthrough first heat exchanger 20 and third heat exchanger 42 sequentiallyin this order during the second cooling operation. Thus, among firstheat exchanger 20 and third heat exchanger 42 each functioning as anevaporator during the second cooling operation (i.e., a heat exchangeron which frost may form), first heat exchanger 20 functioning as acondenser after switching to the first cooling operation can bepositively covered with frost, and third heat exchanger 42 functioningas an evaporator also after switching to the first cooling operation canbe less likely to be covered with frost. As a result, when the operationis thereafter switched to the first cooling operation for defrosting,only first heat exchanger 20 significantly covered with frost can bedefrosted, so that an efficient defrosting operation can be performed.

In refrigerant circuit RCa according to the present second embodiment,an adsorbent (a desiccant material or the like) that adsorbs moisture inair may be applied onto the surfaces of first heat exchanger 20 andsecond heat exchanger 40. Thereby, moisture in air is adsorbed in firstheat exchanger 20 or second heat exchanger 40, so that third heatexchanger 42 can be prevented from being covered with frost.

For example, during the second cooling operation in which first heatexchanger 20 functions as an evaporator, the moisture in the indoor airis adsorbed by the adsorbent of first heat exchanger 20 when the indoorair flows through first heat exchanger 20. Thus, the indoor air flowingthrough first heat exchanger 20 and thereafter blown to third heatexchanger 42 is dried. As a result, third heat exchanger 42 can be lesslikely to be covered with frost.

Further, the operation is thereafter switched to the first coolingoperation to cause first heat exchanger 20 to function as a condenser,and thereby, moisture contained in the adsorbent of first heat exchanger20 can be released to outdoor air. As a result, the adsorbent of firstheat exchanger 20 is dried. Accordingly, when the operation is againswitched to the second cooling operation to cause first heat exchanger20 to function as an evaporator, moisture in the indoor air can beadsorbed again by the adsorbent of first heat exchanger 20.

Third Embodiment

FIGS. 15 to 18 each schematically show an example of the configurationof a refrigerant circuit RCb of a refrigeration cycle apparatusaccording to the present third embodiment. Refrigerant circuit RCbaccording to the present third embodiment is obtained by adding a fourthheat exchanger 44 to refrigerant circuit RCa according to theabove-described second embodiment. Other configurations of refrigerantcircuit RCb are the same as those of refrigerant circuit RCa. Further,other configurations and operations of the refrigeration cycle apparatusaccording to the present third embodiment are the same as those ofrefrigeration cycle apparatus 1 shown in FIG. 1 described above.

Fourth heat exchanger 44 is disposed between the discharge port ofcompressor 10 and first switching valve 60. Fourth heat exchanger 44exchanges heat between the refrigerant discharged from compressor 10 andoutside air.

FIG. 15 is a diagram showing the state during the first coolingoperation of refrigerant circuit RCb. FIG. 16 is a diagram showing thestate during the first switching operation of refrigerant circuit RCb.FIG. 17 is a diagram showing the state during the second coolingoperation of refrigerant circuit RCb. FIG. 18 is a diagram showing thestate during the second switching operation of refrigerant circuit RCb.

The states of compressor 10, first switching valve 60, second switchingvalve 70, first air blower 80, and second air blower 90 during eachoperation are controlled basically in the same manner as that in theabove-described second embodiment.

In the case where frost or moisture adheres to the condenser when firstheat exchanger 20 or second heat exchanger 40 functions as a condenser,the heat exchange efficiency of the condenser changes according to theamount of adherence of frost or moisture. Further, since the heatexchanger is used as a condenser, the amount of adherence of frost ormoisture may change in accordance with the operation, so that the highpressure inside the condenser changes from moment to moment.

In view of the above-described point, in refrigerant circuit RCbaccording to the present third embodiment, fourth heat exchanger 44 isadditionally disposed between the discharge port of compressor 10 andfirst switching valve 60. Thereby, even when the heat exchangerperformance of first heat exchanger 20 or second heat exchanger 40changes, the high pressure can be stably maintained at a constant value.

Further, as shown in FIG. 15 , refrigerant circuit RCb according to thepresent third embodiment is configured such that, during the firstcooling operation, the outdoor air flows through first heat exchanger 20and thereafter is blown to third heat exchanger 42. This can facilitateexchange of heat by fourth heat exchanger 44 serving as a condenser.

[Configuration Examples of First Air Blower 80 and Second Air Blower 90]

The following describes configuration examples of first air blower 80and second air blower 90 used in the refrigeration cycle apparatusaccording to each of the above-described first to third embodiments.

FIGS. 19 and 20 each are a diagram showing a configuration example offirst air blower 80 and second air blower 90 suitable for therefrigeration cycle apparatus according to the above-described firstembodiment. Note that FIG. 19 shows the state during the first coolingoperation (see FIG. 6 ) according to the first embodiment, and FIG. 20shows the state during the second cooling operation (see FIG. 7 )according to the first embodiment.

First air blower 80 includes a fan 81, an air path 82, and an air pathswitch 83.

Fan 81 operates in response to a command from controller 100, and blowsindoor air into air path 82. Air path 82 allows communication betweenthe indoor space to be cooled and each of first heat exchanger 20 andsecond heat exchanger 40. Air path switch 83 is configured to be capableof switching a supply destination of the indoor air between first heatexchanger 20 and second heat exchanger 40 by switching the path in airpath 82 in response to a command from controller 100. Note that thestate of air path switch 83 is switched, for example, by driving a motor(not shown).

Second air blower 90 includes a fan 91, an air path 92, and an air pathswitch 83 that is shared between first air blower 80 and second airblower 90. Fan 91 operates in response to a command from controller 100,and blows outdoor air into air path 92. Air path 92 allows communicationbetween the outdoor space not to be cooled and each of first heatexchanger 20 and second heat exchanger 40. Air path switch 83 isconfigured to be capable of switching a supply destination of theoutdoor air between first heat exchanger 20 and second heat exchanger 40by switching the path in air path 92 in response to a command fromcontroller 100.

During the first cooling operation, air path switch 83 is brought intothe state shown in FIG. 19 while fans 81 and 91 are operated, andthereby, the supply destination of the indoor air can be set to secondheat exchanger 40, and the supply destination of the outdoor air can beset to first heat exchanger 20. During the second cooling operation, airpath switch 83 is brought into the state shown in FIG. 20 while fans 81and 91 are operated, and thereby, the supply destination of the indoorair can be set to first heat exchanger 20 and the supply destination ofthe outdoor air can be set to second heat exchanger 40.

FIGS. 21 and 22 each are a diagram showing a configuration example of afirst air blower 80A and a second air blower 90A suitable for therefrigeration cycle apparatus according to the above-described secondembodiment. Note that FIG. 21 shows the state during the first coolingoperation (see FIG. 11 ) according to the second embodiment, and FIG. 22shows the state during the second cooling operation (see FIG. 13 )according to the second embodiment.

First air blower 80A is obtained by adding air paths 82 a and 82 b andair path switches 83 a and 83 b to the above-described first air blower80. Second air blower 90A is obtained by adding air paths 92 a and 92 band air path switches 83 a and 83 b, which are shared between second airblower 90A and first air blower 80A, to the above-described second airblower 90.

Air path 82 a is formed to supply the air having passed through firstheat exchanger 20 to third heat exchanger 42. Air path 82 b is formed tosupply the air having passed through second heat exchanger 40 to thirdheat exchanger 42. Air path 92 a is formed to supply the air havingpassed through first heat exchanger 20 to the outdoors. Air path 92 b isformed to supply the air having passed through second heat exchanger 40to the outdoors.

Air path switch 83 a is configured to be capable of switching, betweenair paths 82 a and 92 a, the supply destination of the air having passedthrough first heat exchanger 20, in response to a command fromcontroller 100. Air path switch 83 b is configured to be capable ofswitching, between air paths 82 b and 92 b, the supply destination ofthe air having passed through second heat exchanger 40, in response to acommand from controller 100. Note that the states of air path switches83 a and 83 b are switched, for example, by driving a motor (not shown).

During the first cooling operation, air path switches 83, 83 a, and 83 bare brought into the states shown in FIG. 21 while fans 81 and 91 areoperated, and thereby, the supply destination of the outdoor air can beset to first heat exchanger 20 while the indoor air is blown throughsecond heat exchanger 40 and third heat exchanger 42 sequentially inthis order. During the second cooling operation, air path switches 83,83 a and 83 b are brought into the states shown in FIG. 22 while fans 81and 91 are operated, and thereby, the supply destination of the outdoorair can be set to second heat exchanger 40 while the indoor air is blownthrough first heat exchanger 20 and third heat exchanger 42 sequentiallyin this order.

FIGS. 23 and 24 each are a diagram showing a configuration example offirst air blower 80A and second air blower 90B suitable for therefrigeration cycle apparatus according to the above-described thirdembodiment. Note that FIG. 23 shows the state during the first coolingoperation (see FIG. 15 ) according to the third embodiment, and FIG. 24shows the state during the second cooling operation (see FIG. 17 )according to the third embodiment.

First air blower 80A is the same as first air blower 80A shown in FIG.21 described above. Second air blower 90B is obtained by replacing airpaths 92 a and 92 b of second air blower 90A shown in FIG. 21 with airpaths 92 c and 92 d, respectively.

Air path 92 c is formed to supply the air having passed through firstheat exchanger 20 to fourth heat exchanger 44. Air path 92 d is formedto supply the air having passed through second heat exchanger 40 tofourth heat exchanger 44.

During the first cooling operation, air path switches 83, 83 a, and 83 bare brought into the states shown in FIG. 23 while fans 81 and 91 areoperated, and thereby, the outdoor air can be blown through first heatexchanger 20 and fourth heat exchanger 44 sequentially in this orderwhile the indoor air is blown through second heat exchanger 40 and thirdheat exchanger 42 sequentially in this order. During the second coolingoperation, air path switches 83, 83 a, and 83 b are brought into thestates shown in FIG. 24 while fans 81 and 91 are operated, and thereby,the outdoor air can be blown through second heat exchanger 40 and fourthheat exchanger 44 sequentially in this order while the indoor air isblown through first heat exchanger 20 and third heat exchanger 42sequentially in this order.

It should be understood that the embodiments disclosed herein areillustrative and non-restrictive in every respect. The scope of thepresent disclosure is defined by the terms of the claims, rather thanthe description above, and is intended to include any modificationswithin the meaning and scope equivalent to the terms of the claims.

REFERENCE SIGNS LIST

1 refrigeration cycle apparatus, 10 compressor, 20 first heat exchanger,30, 32 decompressing device, 40 second heat exchanger, 42 third heatexchanger, 44 fourth heat exchanger, 51 to 58 pipe, 60 first switchingvalve, 70 second switching valve, 71 container, 72 valve body, 73 to 75flow path, 76 rotation axis, 80, 80A, first air blower, 81, 91 fan, 82,82 a, 82 b, 92, 92 a, 92 b, 92 c, 92 d air path, 83, 83 a, 83 b air pathswitch, 90, 90A, second air blower, 100 controller, RC, RCa, RCbrefrigerant circuit.

1. A refrigeration cycle apparatus switchable between a first operationand a second operation, the first operation being an operation in whichrefrigerant circulates in order of a compressor, a first heat exchanger,a decompressing device, and a second heat exchanger, and the secondoperation being an operation in which the refrigerant circulates inorder of the compressor, the second heat exchanger, the decompressingdevice, and the first heat exchanger, the refrigeration cycle apparatuscomprising: a first switching valve connected to a discharge port of thecompressor, one port of the first heat exchanger, one port of the secondheat exchanger, and one port of the decompressing device; a secondswitching valve connected to a suction port of the compressor, the otherport of the first heat exchanger, the other port of the second heatexchanger, and the other port of the decompressing device; and acontroller configured to control the first switching valve and thesecond switching valve; wherein the first switching valve is configuredto be switchable to one of a first state and a second state, in thefirst state, the discharge port of the compressor is connected to theone port of the first heat exchanger, and the one port of the secondheat exchanger is connected to the one port of the decompressing device,and in the second state, the discharge port of the compressor isconnected to the one port of the second heat exchanger, and the one portof the first heat exchanger is connected to the one port of thedecompressing device, the second switching valve is configured to beswitchable to one of a third state, a fourth state, and a fifth state,in the third state, the other port of the first heat exchanger isconnected to the other port of the decompressing device, and the otherport of the second heat exchanger is connected to the suction port ofthe compressor, in the fourth state, the other port of the second heatexchanger is connected to the other port of the decompressing device,and the other port of the first heat exchanger is connected to thesuction port of the compressor, and in the fifth state, the other portof the decompressing device is connected to the suction port of thecompressor, and the other port of the first heat exchanger isdisconnected from the other port of the second heat exchanger, thecontroller is configured to set the first switching valve to the firststate and set the second switching valve to the third state during thefirst operation, and set the first switching valve to the second stateand set the second switching valve to the fourth state during the secondoperation, and when switching to the second operation is requestedduring the first operation, the controller is configured to perform afirst switching operation to bring the first switching valve into thesecond state and bring the second switching valve into the fifth state,and switch an operation of the refrigeration cycle apparatus to thesecond operation after performing the first switching operation.
 2. Therefrigeration cycle apparatus according to claim 1, wherein whenswitching to the first operation is requested during the secondoperation, the controller is configured to perform a second switchingoperation to bring the first switching valve into the first state andbring the second switching valve into the fifth state, and switch theoperation of the refrigeration cycle apparatus to the first operationafter performing the second switching operation.
 3. The refrigerationcycle apparatus according to claim 2, further comprising an air blowerconfigured to be capable of blowing air to the first heat exchanger andthe second heat exchanger, wherein the controller is configured tocontrol the air blower to stop bloc blowing air to the first heatexchanger and the second heat exchanger during the first switchingoperation and the second switching operation.
 4. The refrigeration cycleapparatus according to claim 3, wherein the air blower comprises a firstair blower configured to be capable of switching a supply destination ofindoor air to be cooled to one of the first heat exchanger and thesecond heat exchanger, and the controller is configured to control thefirst air blower to set the supply destination of the indoor air to thesecond heat exchanger during the first operation, and set the supplydestination of the indoor air to the first heat exchanger during thesecond operation.
 5. The refrigeration cycle apparatus according toclaim 4, wherein the air blower comprises a second air blower configuredto be capable of switching a supply destination of outdoor air not to hecooled to one of the first heat exchanger and the second heat exchanger,and the controller is configured to control the second air blower to setthe supply destination of the outdoor air to the first heat exchangerduring the first operation, and set the supply destination of theoutdoor air to the second heat exchanger during the second operation. 6.The refrigeration cycle apparatus according to claim 4, furthercomprising a second decompressing device and a third heat exchanger thatare disposed between the second switching valve and the suction port ofthe compressor.
 7. The refrigeration cycle apparatus according to claim6, wherein the indoor air is blown in order of the second heat exchangerand the third heat exchanger during the first operation, and blown inorder of the first heat exchanger and the third heat exchanger duringthe second operation.
 8. The refrigeration cycle apparatus according toclaim 7, wherein the first heat exchanger and the second heat exchangereach have a surface onto which an adsorbent serving to adsorb moisturein air is applied.
 9. The refrigeration cycle apparatus according toclaim 6, further comprising a fourth heat exchanger disposed between thedischarge port of the compressor and the first switching valve.